Safety belt buckle with twist bar



-27,1970 F. G. HUG -Es 3,491,415 SAFETY BELT BUCKLE WITH TWIST BAR 2 Sheets-Sheet 1 Ease/CK G-HUGHES Filed April 22, 1968 Jan. 27, 1970 F. G. HUGHES. 6, 9

SAFE TY BELT BUCKLE WITH TWIST BAR Filed April 22. 1968 2 Sheets-Sheet 2 'J'NvE/vToQ lfase/cx G. Hum/5s i/m, @wm

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United States Patent 3,491,415 SAFETY BELT BUCKLE WITH TWIST BAR Frederick G. Hughes, Santa Ana, Califi, assignor to American Safety Equipment Corp. of California, Sherman Oaks, Calitl, a corporation of California Filed Apr. 22, 1968, Ser. No. 723,167 Int. Cl. A441) 19/00 US. Cl. 24-230 6 Claims ABSTRACT OF THE DISCLOSURE A metal-to-metal type safety belt buckle for positively restraining movement of a tongue plate insertable therein with respect to the buckle and including push button release actuating means and unlatching twist means disposed between the metal tongue plate and a latch for displacing the tongue plate and latch away from one another upon actuation of the push button.

Metal-to-metal safety belt buckles are well known in the prior art. Recently, because of the widespread use of safety belt systems in automobiles, it has been found desirable to provide a safety belt buckle which has a push button actuating means. Unlike the pivoted latch-type of safety belt buckles, push button actuated buckles afford very little leverage for disengaging the metal tongue plate from the buckle. However, other advantages of push button actuating buckles have made this type of buckle preferable.

The importance of leverage in the actuating member will become apparent when considering that it is an important requirement for safety belt systems to provide quick release subsequent to a collision or accident in which the vehicle is involved. For various reasons, it is necessary that the safety belt buckle actuating member can be easily located and may be easily operated notwithstanding the orientation of the vehicle. That is, in the event that the vehicle comes to rest on its roof or sides, the occupant will be restrained by the seat belt and considerable tension will be placed on the belts which is transmitted to the buckle and tongue plate. Such tension will cause binding between the tongue plate and buckle latch element causing considerable resistance to move ment of the release actuating mechanism.

Accordingly, it is a general object of the present invention to provide a safety belt buckle which overcomes the disadvantages of prior art buckles requiring considerable force for effecting release of the tongue plate from the buckle when the safety belt system is under tension.

It is another object of the present invention to provide a safety belt buckle for use in conjunction with a metal tongue plate having an opening, wherein the buckle is provided with unlatching twist means normally disposed between the tongue plate and latch provided in the buckle which can be easily operated through a push button mechanism.

It is yet another object of the present invention to provide a safety belt buckle for use in a safety belt restraint system in conjunction with a metal tongue plate connected to a second safety belt strap and in which the buckle receives the tongue plate and locks the tongue plate therein through a biased latching member and includes an unlatching twist means disposed between the latch member and tongue plate which is operable with little force for separating the tongue plate and latch member regardless of the amount and direction of load between the tongue plate and buckle.

Generally stated, the present invention provides a safety belt buckle having a base and opposed side walls, a latch including an upwardly projecting locking element mounted for movement with respect to the base, and is adapted to "ice receive a tongue plate having an aperture which engages the locking element to prevent withdrawal and is restrained against upward movement. A push button actuating member is provided to operate an unlatching twist member which displaces the latch and tongue plate away from one another so as to effect release of the tongue plate from the buckle with minimal effort irrespective of loading on the safety belt straps.

Other objects and advantages of this invention will be readily apparent from the following description when considered in connection with the appended drawings:

In the drawings:

FIG. 1 is an exploded perspective view of the seat belt buckle of the instant invention;

FIG. 2 is a top plan view of the seat belt buckle of FIG. 1 with the tongue plate shown in phantom lines;

FIG. 3 is a side cross-sectional view taken substantially along the plane IIIIII of FIG. 2, but with the tongue plate removed;

FIG. 4 is a view similar to FIG. 3 of the seat belt buckle with the tongue late inserted;

FIG. 5 is a view similar to FIG. 4 but showing the push button and latch member in release condition; and

FIG. 6 is a detailed side cross-sectional view of a portion of the buckle and tongue plate.

Referring now to the drawings, there is shown an exemplary embodiment of a safety belt buckle 20 attached to one end of a safety belt strap 21 by means to be described more fully hereinafter. Buckle 20 is adapted for use with a complementary metal tongue plate 23 having a rectangular opening 24 and attached to the end of a second safety belt strap. Buckle 20 generally comprises a base 26 and a pair of opposed side walls 27, 28. Buckle 20 also comprises a latch 29, a latch spring 30, twist lever 31, push button 32, and a load bar 33. One end of belt 21 is adjustably disposed around the load bar 33 for interconnecting buckle 20 and the safety belt strap 21. As seen best in FIG. 1, base 26 is provided with an opening 35 through which the free end of safety belt strap 21 is passed around load bar 33.

With continued reference to FIG. 1, it will also be seen that the forward end of base 26 is provided with an upstanding flange 36, the upper edge of which will define the lower edge of a rectangular opening together with the buckle cover (not shown) through which the tongue plate 23 is inserted into buckle 20. Each of the opposed side walls 27, 28 is provided with means for restraining upward movement of the tongue plate when inserted into the buckle which in the exemplary embodiment comprise a pair of longitudinally extending projections 37, 38 respectively, normally disposed in a plane immediately above the plane of tongue plate 23 when inserted in the buckle.

The latch plate 29 may include an upper face 40 having an offset portion 41 forming a locking element receivable within opening 24 of tongue plate 23 when inserted in buckle 20 to effect locking of the tongue plate within the buckle.

Latch plate 29 is normally biased upwardly away from base 26 by spring means 30 having a reentrantly folded portion 45 for abutting upstanding flange 36 and receiving the forward edge of latch 29. The reentrantly folded portion 45 of spring means 30 is connected to a laterally extending section 46 normally engaging the lower surface of latch 29' and a pair of downwardly depending legs 47, 48 having upstanding foot portions 49, 50 respectively, which engage tabs 51, 52 struck from opposed side walls 27, 28, respectively.

Latch 29 also includes a downwardly depending portion 55 from which a pair of legs 56, 57 extend rearwardly. The forward edge 58 of latch 29 after insertion into the reentrantly folded portion 45 of spring means 30 is positioned on base 26 with forward edge 58 in abutting contact with upstanding flange portion 36 and below striking tabs 60, 61 Which restrain upward movement of the forward edge of latch 29.

Unlatching twist means in the exemplary embodiment may comprise a twist lever 31 including a forward tongueengaging tab 65 connected to a lever portion 66 having opposed stub axles 67, 68 on the outboard ends thereof to be received within openings 70, 71 formed in opposed side walls 27, 28 respectively.

As best seen in FIG. 6, side wall lever-receiving openings 70, 71 have an arcuate configuration for receiving the substantially rectangular cross-section lever stub axles 67, 68 for reasons more fully described hereinafter.

Lever portion 66 of twist lever 31 has a pair of leg portions 75, 76 disposed on the outboard ends thereof, each of which has a foot portion 77, 78 respectively.

Actuating means in the exemplary embodiment may comprise push button 32 including a laterally extending axle portion 80, supporting a substantially rectangular button 81 which will normally be disposed within an opening in a cover (not shown) for the buckle 20 and the upper surface of which will be preferably flush with the upper surface of the cover. Push button 32 also includes stub axle portions 82, 83 of substantially rectangular cross-section to be received in openings 84, 85 in side walls 27, 28 respectively. Also mounted adjacent the outboard ends of axle portion 80 of push button 32 are foot engaging portions 86, 87 normally engaging foot portions 77, 78 respectively, of twist lever 31.

It should be appreciated that while push button 32 is illustrated as supported by the openings 84, 85 in side walls 27, 28 through stub axles 82, 83 for motion toward and away from base 26, other means for confining button 81 for vertical movement, which may be supported by a cover for buckle 20 will provide the necessary function. It should also be appreciated that while the upstanding legs 77, 78 of twist lever 31 are shown as flat vertical portions, such legs may be formed with an arcuate or similar shape so as to provide a suitable bearing surface for contact with foot engaging portions 86, 87 of push button 32.

The load bar 33, about which the seat belt strap 21 is looped, includes flat rectangular stub axles 90, 91 which are received for slidable movement in elongated openings 92, 93 in side walls 27, 28 respectively, of the buckle 20.

The seat belt buckle 20 is assembled by first inserting spring means 30 between the opposed side walls 27 and 28 and resting upon base. 26 with the reentrantly folded portion 45 abutting the upstanding flange 36 of the base and the upstanding foot portions 49 and 50 of the spring means positioned forwardly of the tabs 51 and 52. The forward edge 58 of the latch 29 is then inserted into the reentrantly folded portion 45 and below the tabs 60, 61 in upstanding flange 36. The stub axles 67, 68 of the twist lever 31 may then be inserted in the openings 70, 71 in the opposed side walls. Similarly, the push button 32 may be inserted in the openings 84, 85 in the opposed side walls by vertically disaligning the stub axles 82, 83. Finally, the safety belt strap 21 is positioned around load bar 33 and the load bar is horizontally disaligned so that stub axles 90, 91 may be inserted into the rectangular elongated openings 92, 93 in the opposed side walls. A suitable cover may then be secured to the buckle 20 in a manner well known in the art.

By comparison of the device as illustrated in FIGS. 3 through 5, operation may be readily described. As seen in FIG. 3, where the tongue plate 23 is not inserted in the buckle 20, spring means 30 biases the latch 29 so that the locking element 41 extends into the plane to be occupied by the tongue plate 23. Entry of the tongue plate 23 is initially guided by the upper edge of upturned flange 36 on base 26 and a portion of thecover, and is further guided upon entry by contact with the projections 37, 38 on the side walls 27, 28 so that the tongue plate bears against the lower surface of these projections and forces the locking element 41 and latch 29 downwardly. When the forward end of the tongue plate 23 passes the edge of locking element 41 the locking element will be biased upwardly into opening 24 of the tongue plate. The tongue plate is then locked to buckle 20, as seen in FIG. 4.

Release of the tongue plate from the buckle is illustrated in FIG. 5, wherein it will be seen that depression of the button 81 by the occupant restrained by the safety apparatus will cause feet 77, 78 on unlatching twist lever 31 to rock, i.e., to move downwardly and pivot s0 that the twist lever rotates about the forward edge of the tab 65. The stub-axles 67, 68 on twist lever 31 are free to float in the arcuate openings 70, 71 in the opposed side walls 27, 28. The twisting or prying movement of lever 31 causes the leg portions 75, 76 to depress the rearwardly extending legs 56, 57 of latch 29 so as to lower locking element 41 from the path of tongue plate 23, whereby the tongue plate is released from the buckle.

Subsequent to an accident, it may be desirable to quickly release tongue plate 23 from connector 20. Under some conditions however, the safety belt straps may be under considerable tension which may not only urge tongue plate 23 longitudinally out of connector 20 but may also apply a lateral force to plate 23 so that the forward edge thereof may be forced downwardly. Under such circumstances, the twist lever 31 will still easily function under normal manual depression force on button 81. As may perhaps best be seen from FIG. 6, as the forward end 100 of tongue plate 23 is forced downwardly during actuation of the button 81, the entire twist lever will be forced downwardly since the stub-axles 67, 68 of twist lever 31 may move downwardly in arcuate openings 70, 71 in the opposed side walls. Notwithstanding this downward movement of the forward portion 100 of tongue plate 23, the unlatching means is as effective as if the tongue plate had no tension thereon, and the lever arm through which the depression force acts remains the same.

It will be appreciated that the lateral forces on the tongue plate are not directly transmitted to a fixed pivotal axis as if the forward end of the twisting means 31, i.e., the tab 65, was a fixed pivot axis. In the latter configuration, during impact of the vehicle in which the safety belt restraint system is used, the forces transmitted through the seat belt strap and to the tongue plate being of considerable magnitude would likely result in structural failure of such pivotal axis. However, in the present invention, such lateral forces cause the forward end 100 of the tongue plate to be depressed and will simply tend to rotate twist lever 31 but does not cause any depression of locking element 41, relative to tongue plate 23 since the twist means is free to move downwardly. Thus, the tongue plate is continuously locked in buckle 20 and does not transmit any forces which tend to produce structural failure of buckle 20.

It is to be understood that the exemplary embodiment of the improved safety belt buckle herein disclosed and described is presented only for the purpose of explanation and illustration and is not intended to indicate limits of the invention, the scope of which is defined by the following claims.

I claim:

1. In a safety belt buckle having a base and opposed side walls, a latch supported for motion between two extreme positions with respect to the base, the latch having a locking element, actuating means supported for motion toward and away from the base, a tongue plate adapted to be inserted into the buckle for releasable engagement with the locking element on the latch, the improvement comprising:

unlatching twist means supported in said buckle in operative engagement with the actuating means and positioned between the inserted tongue plate and the latch for displacing the tongue plate and latch away from one another to release the tongue plate from the buckle upon movement of the actuating means.

2. In a safety belt buckle having a base and opposed side walls, a latch supported for motion between two extreme positions with respect to the base, a locking element projecting upwardly from the latch with respect to the base, actuating means supported for motion toward and away from the base, a tongue plate-having an aperture therein adapted to be inserted above thelatch so that the locking element on the latch engages the aperture of the tongue plate when inserted in the buckle, means for restraining movement of the tongue'plate. upwardly with respect to the base when the plate is inserted in the buckle, the improvement comprising:

unlatching twist means supported in operative engagement with the actuating means andbetween the end of the tongue plate and the latch for displacing the tongue plate and latch away from one another upon movement of the actuating means toward the base.

3. The provision of claim 2 wherein said unlatching twist means comprises a lever overlying one end of the latch and underlying the end of 'the tongue plate, said lever being supported by the opposed side walls for rocking movement. (I

4. The provision of claim 3 wherein, said lever includes a shaft supported by said opposed side walls for combined pivotal and translatory movement and includes a first arm extending in a firstdirection from the pivot axis adjacent the lower surface of the tongue plate and a second arm extending in the opposite'direction adjacent the upper surface of the latch so that upon movement of the actuating means towards the base, said first arm bears upwardly on the tongue plate and said second arm bears downwardly on the latch so as to separate the tongue plate and latch.

5. The provision of claim 4 wherein said lever axle comprises stub axles on opposed ends of said lever, each of said axles being substantially rectangular in configuration, each of the opposed side walls having arcuate openings for receiving one of said stub axles so that said axles may move simultaneously arcuately and pivotally about the axis of the axles.

6. A safety belt buckle comprising:

a base and opposed side walls;

a latch supported at one end by said base for pivotal movement with respect to said base and having a locking element projecting upwardly therefrom;

means for biasing the latch away from the base;

actuating means supported for motion toward and away from base;

said buckle being adapted to receive a tongue plate having an aperture therein above the latch so that the locking element on the latch engages the aperture of the tongue plate when inserted in the buckle;

means for restraining movement of the tongue plate upwardly with respect to the base when the plate is received in the buckle;

unlatching twist means including a lever overlaying one end of the latch and underlying the end of the tongue plate when the plate is received in the buckle, and stub axles disposed on opposite ends of said lever, each of said axles being substantially rectangular in configuration;

each of said opposed side walls having an arcuate opening for receiving one of said stub axles so that said lever is supported for rocking movement, whereby movement of the actuating means towards the base displaces the tongue plate and latch away from one another so as to release the tongue plate for withdrawal from the buckle.

References Cited UNITED STATES PATENTS r 3,131,451 5/1964 Fisher. 3,364,531 1/ 1968 Moss.

FOREIGN PATENTS 1,377,155 9/1964 France.

BERNARD A. GELAK, Primary Examiner 

